Mailbox folders

On the left side you see a hierarchical list of all folders in your mailbox. Folders can be used to file email messages by topic, sender or whatever you choose for organization.
Incoming messages usually appear in the Inbox folder which is the first item in the folder list. There are some special folders which are used by the system to store sent (Sent) or deleted (Trash) messages and where not-yet-sent message drafts (Drafts) are saved. These system folders are indicated with special icons.

The number of unread messages in each folder is displayed at the right border of the folder list.

Click a folder in the list to show the contained messages in the message list on the right. The currently selected folder is highlighted in the list.

Folders with hidden subfolders are indicated with a small icon which can be clocked to expand or collapse the folder tree.

Folder operations
In the footer of the folder list, the Folder actions icon shows a list of folder-related actions when clicked. Most of the actions in the menu affect the currently selected folder.

Compact
This action will compress the folder size by finally deleting messages that have been marked for deletion.
Empty
This will delete all messages in the selected folder permanently. Be very careful with this operation as it cannot be undone. For security reasons, this action is only available for the Trash and Junk folders.
Manage folders
This menu item will take you the settings section when you can manage the mailbox folders. This is where you can create, delete, rename or re-organize your email folders.
Quota display
If your mailbox is limited by a maximum size, the quota display located in the footer of the folder list indicates the current usage of the available disk space. Move the mouse pointer over the percentage display to see the real numbers of your quota usage.